Rubber goods such as tire treads often are made from elastomeric compositions that contain one or more reinforcing fillers such as, for example, particulate carbon black and silica; see, e.g. The Vanderbilt Rubber Handbook, 13th ed. (1990), pp. 603-04.
There is continuing interest to provide tires with a high level of handling, steering response, and low fuel consumption. A common method of increasing the steering response of the tire is to use a tread rubber with high stiffness. High stiffness compounds typically have a high dynamic storage modulus (G′). Conventional compounding techniques used to increase the dynamic storage modulus include using a high filler loading, using a filler with a high surface area, and using less softener. However, each of these conventional methods has performance and processing, tradeoffs.
For example, the above mentioned conventional techniques can increase the hysteresis of the rubber compound. Increasing the hysteresis of the rubber results in more energy loss as heat, and thus increases fuel consumption.
In addition, increasing the flier loading, using a filler with a high surface area, and lowering the softener level can have a negative effect on processing, as each of these increases the time it takes to disperse the filler into the rubber and increases the viscosity of the rubber composition.